Locating device for temperature compensated parallax barrier supporting system

ABSTRACT

Cooperating means formed between a temperature compensating member having an expansion loop and a sidewall of a parallax barrier are provided to insure centering of the loop within a preformed opening in the barrier sidewall. The cooperating means comprise protruding portions and matching receiving openings therefor, either of which may be formed on either member with the mating portion formed on the other member.

imite States Patent [72] Inventor Benedict F. Vitale Auburn, N.Y.

[21] Appl. No. 9l90 Division of Ser. No. 786,183, Dec. 23, 1968, Pat.No. 3,573,526.

[45] Patented Aug. 17, 1971 [73] Assignee Sylvania Electric Products,Inc.

[54] LOCATING DEVICE FOR TEMPERATURE COMPENSATED PARALLAX BARRIERSUPPORTING SYSTEM 3 Claims, 5 Drawing Figs.

[52] U.S.Cl 313/85 S, 313/283 [51] Int. Cl. H0lj 31/20 [50] Field ofSearch 313/69 C,

70 c, 85 s 92 PD, 92 B [56] Reierences Cited UNITED STATES PATENTS3,330,980 7/1967 Shrader 3 l3/85 3,524,096 8/1970 Kuryla et al. 313/85Primary Examiner--Robert Segal Attorneys-Norman J. O'Malley, Donald R.Castle and William H. McNeil] ABSTRACT: Cooperating means formed betweena temperature compensating member having an expansion loop and asidewall of a parallax barrier are provided to insure centering of theloop within a preformed opening in the barrier sidewall. The cooperatingmeans comprise protruding portions and matching receiving openingstherefor, either of which may be formed on either member with the matingportion formed on the other member.

PATENTED AUG] 7 I97! SHEET 1 BF 2 INVENTOR. BENEDICT F VITALE ATTOE N EYPATENTEU M181 7197:

SHEET 2 [1F 2 INVENTOR. BENEDICT F VI ALE ATTOR N EY CROSS-REFERENCE TORELATED APPLICATION I This application is a division of Ser. No.786,183, filed Dec. 23, 1968 and assigned to the assignee of the presentinvention.

BACKGROUND OF THE INVENTION with a foraminated pattern which is inaccurate registry withthe phosphor pattern on the screen. Duringoperation of the tube the barrier enlarges due to the head generatedtherein by the impingement of the electron beams thereon. This increasein size has, in'the past, caused some loss of registration in the tuberesulting in an improper color balance. To counteract this effect, thesupporting springs have been attached to the barrier sidewalls throughthe intermediary of a bimetallic element or baseplate which is providedwith an expansion loop or hinge. The bimetallic base plate utilizes theheat generated in the barrier to change the position of the barrierduring operation of the tube in a controlled manner to substantiallymaintain the desired registratiomFor a more detailed operation of thebimetallic device, reference may be had to US. Pat. No. 3,330,980. 1

The expansion loop on this element, when installed on a parallaxbarrier, projects inwardly toward the center of the tube. To accommodatethis projection a slot, larger in size than the loop, is provided in thebarrier sidewall. To insure proper operation of the device, the loopmust be centered within the opening to insure its nonbinding expansionand contraction. In the past this has been a tedious and time consuminghand operation with an operator attempting-to visually center the deviceand maintain it in position while it was welded or otherwise permanentlyfixed in position. Besides the disadvantages named above, there was noparticular guarantee of success.

OBJECTS AND SUMMARY OF THE INVENTION It is, therefore, an object of theinvention to enhance the operation of color cathode-ray tubes employingthese devices.

It is another object of the invention to insure nonbinding operation ofthese devices.

It is yet another object of the invention to remove operatorerror as afactor in the installation of such devices.

These and other objects are accomplished in one aspect of the inventionby the provision, within a color cathoderay tube of the class described,of cooperating baseplate locating means formed on the baseplate and thesidewall of the para]- lax barrier to achieve substantially centrallocation of an expansion loop within a preformed opening whereby itsnonbinding action during operation is insured.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 5 is a partial perspective viewillustrating still another embodiment of the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS For a better understanding ofthe present invention, together with other and further objects,advantages and capabilities thereof, reference is made to the followingdisclosure and appended claims in connection with the above-describeddrawings.

Referring now to the drawings with greater particularity, there is shownin FIG. I a color cathode-ray tube 10 having a faceplate 12 with apatterned phosphor screen 14 disposed on the interior surface thereof. Aperipheral sidewall 16 extends from faceplate l2 and joints asubstantially funnel-shaped body 18. The narrow end of the funnelterminates in a cylindrical neck 20 which encloses an electron source22, which is typically in the form of three electron guns. A parallaxbarrier 24 is releasably mounted within the tube adjacent the screen.The tube is evacuated as is conventional in'the art and is provided withsuitable leads (not shown) for making electrical connection to theproper components.

The parallax barrier 24 comprises a relatively fragile apertured portion26 which is fixed at its peripheral edge to a relatively rigid frame 28.The frame provides the parallax barrier sidewalls 30 to which thesupporting springs are attached. The configuration of the apertures inportion 26 may be either substantially circular or rectangular dependingupon the screen pattern.

Referring now to FIG. 2 there is shown a section of parallax barrier 24together with one of its spring support systems 32. Normally, in currenttubes, either three or four such systems are utilized; however, sincethey are all substantially identical, only one is shown here. The springsupport system comprises a bimetallic baseplate 34 having upper andlower sections 36 and 38 respectively, joined together by an expansionloop 40 which projects from the plane of the baseplate inwardly towardthe center of the tube 10. To accommodate the loop 40 there is provideda substantially rectangular loop-receiving opening 42 formed in sidewall30.

A leaf spring 44 is attached to upper portion 36 of the baseplate 34 andprojects outwardly therefrom. The free end of spring 44 is provided withan aperture 46 for engaging a stud 48 which is provided on the interiorsurface of peripheral wall 16.

In order for the loop to function properly, opening 42 must be largeenough to provide for freedom of movement thereof during operation.Further, even when the opening is sufficiently large, care must be takento assure that the loop is properly centered therein and is not bindingagainst one of the edges of the opening.

To insure this desirable result, there is provided cooperating baseplatelocating means formed on the baseplate 34 and the sidewall 30. In theembodiment shown in FIG. 2 the locating means comprises a substantiallyelongated protrusion 50 extending from the plane of the baseplate 34toward the center of the tube. A matchingly configured second opening 52is formed in sidewall 30 to receive protrusion 50 with a substantiallysnug fit. The second opening 52 should be just enough larger thanprotrusion 50 to allow for easy entry thereinto without allowing anyroom for slop, since this would permit the baseplate 34 to bemisaligned. The actual amount of tolerance allowed between the secondopening 52 and the protrusion 50 will depend in part upon the materialsbeing utilized and the cost factor willing to be borne by the tubeproducer. I

An alternate embodiment of the locating means is shown in FIG. 3 whereinit comprises at least two protuberances 54 and 56 respectively which, inthis instance, are shown as being formed on barrier sidewall 30.Matching openings 58 and 60 are provided in baseplate 34. Obviously, theconditions may be reversed and the protuberances may be formed on thebaseplate with the openings in the sidewall. In the instant case theprotuberances are shown as being cylindrical; however, it is to beunderstood that this is illustrative only and that other configurationsmay be employed.

Another embodiment of the invention is illustrated in FIG. 4 wherein thelocating means comprises a single, substantially elongated protrusion 62extending outwardly from the plane of sidewall 30. A matching opening 64is provided in baseplate 34. The protrusion 62 may be punched from thesidewall 30 or it may be an additional member welded thereon.

A still further embodiment is shown in FIG. 5 wherein the locating meanscomprises an adjacent pair of edges of baseplate 34; for example, 66 and68 respectively. The complimentary locating means on the sidewall 30then takes the form of a substantially L-shaped bracket 70 having a leg72 and a leg 74. In this embodiment, fitting the edge 66 against leg 74and edge 68 against leg 72 will provide the desired alignment.

In each of the above-described embodiments, after the cooperativecoupling of the locating means, the baseplate is pennanently affixed inposition on the sidewall 30 by means of welding or other suitablemethod.

Thus, it will be seen that there is provided by this invention novelmeans for enhancing the operation of color cathode-ray tubes employingbimetallic, temperature-compensating devices. Nonbinding action of theexpansion loop is insured and the factor of operator-error is removed.

While there have been shown and described what are at present consideredthe preferred embodiments of the invention, it will be obvious to thoseskilled in the art that various changes and modifications may be madetherein without departing from the scope of the invention as defined bythe appended claims.

I claim: 1. A color cathoderay tube having an envelope and a patterned,mosaic screen therein; a parallax barrier mounted within said tubeadjacent said screen comprised of a relatively fragile apertured portionand a relatively heavy frame having a wall, said apertured portion beingattached at its peripheral edge to said wall of said frame, each of theapertures in said tending loop extending therefrom, said loop beingresponsive, to temperature changes within said tube and being formedbetween first and second ends of said baseplate; means for attaching afirst end of each of said baseplates to said wall of said frame; anopening formed in said wall of said frame to receive said loop;cooperating baseplate locating means formed on said first end of saidbaseplate and said wall to achieve substantially central location ofsaid loop within said opening whereby its nonbinding action is insured;said cooperating baseplate locating means comprising a substantiallyrectangular protrusion extending from the plane of said wall and asubstantially rectangular opening of similar size in said baseplate,said opening providing a snug fit for said rectangular protrusion; alike plurality of spaced studs projecting internally of said tube andattached to said envelope and a like plurality of leaf springs eachhaving one end attached to one of said studs and the other end affixedto one of said second ends of one of said baseplates.

2. The invention of claim 1 wherein said rectangular protrusion isformed as a separate element and is welded to said wall.

3. The invention of claim 1 wherein said rectangular protrusion issubstantially centrally located beneath said aperture in said framewall.

1. A color cathode-ray tube having an envelope and a patterned, mosaicscreen therein; a parallax barrier mounted within said tube adjacentsaid screen comprised of a relatively fragile apertured portion and arelatively heavy frame having a wall, said apertured portion beingattached at its peripheral edge to said wall of said frame, each of theapertures in said barrier being aligned with particular areas of saidmosaic screen; said mounting for said barrier in said tube includingmeans for maintaining said alignment during tube operation, saidlast-named means comprising: a plurality of temperature compensatingmounting members spaced about said wall of said frame, each comprising abimetallic baseplate formed from contiguous materials having differentthermal coefficients of expansion and being formed to have a protrudingextending loop extending therefrom, said loop being responsive totemperature changes within said tube and being formed between first andsecond ends of said baseplate; means for attaching a first end of eachof said baseplates to said wall of said frame; an opening formed in saidwall of said frame to receive said loop; cooperating baseplate locatingmeans formed on said first end of said baseplate and said wall toachieve substantially central location of said loop within said openingwhereby its nonbinding action is insured; said cooperating baseplatelocating means comprising a substantially rectangular protrusionextending from the plane of said wall and a substantially rectangularopening of similar size in said baseplate, said opening providing a snugfit for said rectangular protrusion; a like plurality of spaced studsprojecting internally of Said tube and attached to said envelope and alike plurality of leaf springs each having one end attached to one ofsaid studs and the other end affixed to one of said second ends of oneof said baseplates.
 2. The invention of claim 1 wherein said rectangularprotrusion is formed as a separate element and is welded to said wall.3. The invention of claim 1 wherein said rectangular protrusion issubstantially centrally located beneath said aperture in said framewall.